Well you could always get a nice pot and put the cym and the existing pot in it for the time being.
My cym also seemed to be growing too fast for its own good, but maybe it is normal. In my case it's 8 growths that sort of appeared overnight. It seems to be adding nearly a third of its size every year. I know that they like to be pot bound so if you do repot, maybe the current size pot would be enough until next year. When I bought mine, it had literally exploded the plastic pot it was in. Those are strong roots!
As for dividing it, I think the minimum is of 3 bulbs per division, so yours is still too small. Besides, they put on a nicer show if you have a bigger plant!
And nice plumies by the way! I love them, but just don't have the space for any more plants indoors during the winter.
